Novel polyester resins containing spiroacetal units

ABSTRACT

The invention provides a cured polyester resin consisting of a co-polymer of at least one dicarboxylic acid and at least one dihydroxy alcohol wherein a part of the dicarboxylic acid and/or the dihydroxy alcohol is a compound of the formula:   WHEREIN EACH OF R,R&#39;&#39; is a divalent organic group and each X is a carboxyl group or acid forming derivative thereof or a hydroxyl group, the said polyester containing a proportion of ethylenically unsaturated linkages being cured by cross linking with an ethylenically unsaturated compound such as styrene.

United States Patent [191 Rockey Jan. 30, 1973 NOVEL POLYESTER RESINSCONTAINING SPIROACETAL UNITS Kenneth William Rockey, Cookham, Berkshire,England Albright & Wilson Limited, Oldbury, near Birmingham,Warwickshire, England Filed: Aug. 14, 1970 Appl. No.: 63,937

Inventor:

Assignee:

US. Cl. ..260/86l, 260/75 UA Int. Cl. ..C08121/00, C08g 17/10 Field ofSearch ..260/861, 75 UA References Cited UNITED STATES PATENTS 7/1960Caldwell et al ..260/75 11/1966 Leech et al ..260/75 PrimaryExaminerWilliam H. Short Assistant Examiner-E. Nielsen AttorneyHerbertH. Goodman [57] ABSTRACT The invention provides a cured polyester resinconsisting of a co-polymer of at least one dicarboxylic acid and atleast one dihydroxy alcohol wherein a part of the dicarboxylic acidand/or the dihydroxy alcohol is a compoundwula: v

16 Claims, No Drawings NOVEL POLYESTER RESINS CONTAINING SPIROACETALUNITS The present invention relates to novel polyester resins of theethylenically unsaturated type.

it is well known to react together dicarboxylic acids, such as phthalicand glycols such as ethylene glycol to form a polyester, for example ofthe fiber forming type. It is also known to include a proportion ofethylenically unsaturated material, such as maleic acid, among thereagents so as to form an unsaturated polyester. Unsaturated polyestersmay be cured with styrene or similar vinylic compounds to form rigidresins which have the advantage of a hard surface. One factor which hashitherto tended to restrict the use of cured polyester resins, however,is their brittleness.

We have now discovered a novel ingredient for incorporation inunsaturated polyester compositions which provides cured resins havingimproved flexibility and reduced brittleness.

The present invention provides an ethylenically unsaturated co-polymerof at least one dicarboxylic acid and at least one dihydroxy alcohol,wherein a part of the dicarboxylic acid and/or the dihydroxy alcohol isa compound of the formula:

wherein each of R,R' is a divalent organic group and each X is acarboxyl group or ester forming derivative thereof or a hydroxyl group.

The invention further provides resins comprising a polyester of theinvention cured with a vinylic compound.

The polyester resins of the present invention may conveniently beprepared by reacting together one or more dicarboxylic acids, acidanhydrides, acid chlorides or alkyl esters, and one or more dihydroxyalcohols. Hereinafter, reference to the use, as reagent in thepreparation of unsaturated polyesters, of dicarboxylic acids is to beconstrued as including a reference to such derivatives of thedicarboxylic acids as are condensible with dihydroxy alcohols to formpolyesters, for example anhydrides, acid chlorides and transesterifiableesters, such as methyl esters or other esters in which the alcoholicmoiety is more volatile than the dihydroxy alcohol. Preferably thedicarboxylic acid is an alkyl, cycloalkyl, aryl or aralkyl dicarboxylicacid or a halogenated derivative thereof. In general it is preferred touse acids containing from 3 to 20, preferably four to carbon atoms. Thedicarboxylic acid reagent is preferably a mixture of fumaric or maleicacid, phthalic acid and a compound of formula (1) wherein X is acarboxyl group or esterifiable derivative thereof. Other dicarboxylicacids which may be present as, or as part of, the acid reagent includetetrahydrophthalic acid, endomethylene tetrahydrophthalic acid, sebacicacid, adipic acid, azelaic acid, malonic acid, cyclohexane dicarboxylicacid, terepthalic acid, isophthalic acid, tetrachlorophthalic acid,hexachloroendomethylenetetrahydrophthalic acid, acid and succinic acid.

The dihydroxy alcohol is preferably ethylene or propylene glycol, or mayinclude unsaturated glycols 01 oi Cl 01 l l l mocmomimnQ where each n isfrom 1 to l0; or of the formula;

kart-om orr 011F011. HOCH CH- CH CHOH GHQ-{1H2 H3 CH2C 2 and compoundsof the formula 1 wherein X is a hydroxyl group. The alcoholic reagentmay also contain a small proportion of polyhydroxy alcohols such asglycerol, trimethylol propane or pantaerythritol. in addition a minorproportion of monofunctional carboxylic acid or alcohol may be includedas a chain terminator, e.g. acetic acid, benzoic acid, lauric acid,myristic acid, lauryl alcohol, cetyl alcohol benzyl alcohol.

The compounds of formula 1 are spiroacetals which may for example beobtained by reacting pentaerythritol either with an aldehyde of theformula XRCHO where X has the same significance as hereinbefore, or withan aldehyde of the formula NC-R-CHO and hydrolyzing the nitrile group toform a carboxyl group. Preferably R is a divalent hydrocarbon group forexample: a saturated hydrocarbon group having from 1 to 20 andpreferably two to 12 carbon atoms such as a methylene, ethylene orpropylene group, or an 01,0) substituted pentane, hexane or heptanegroup; a cycloaliphatic group such as a cyclohexyl group; a divalentaryl group such as an o, m or preferably p phenylene group; an alkarylgroup such as a p-benzyl or ethyl phenyl group; or an olefinic groupsuch as a butene group. The group R may also comprise an alkylpolyoxyalkylene or polyoxyalkylene carboxylate group. Examples ofsuitable compounds of the formula l in clude: R=--Cl-l Cl-l X=COOH;R=-C,H,,-, X=COOMe; R=(CH CH 0),,CH CH X=Ol-l; R= CH,CH C0(OCH CH X-OH;and R=Cl-l CH=CH CH,, X=COC. A preferred compound is l (R= (CH --,X=COOMe).

The alcoholic reagents are preferably employed in stoichiometric excess,e.g. up to 50 percent molar excess. Preferably the molar proportion ofethylenically unsaturated acid and/or alcohol included in the reagentsis from 25 to percent e.g. from 35 to 55 percent most preferably from 45to 55, based on the total molar proportion of acid. The proportion ofspiroacetal of formula 1 may be from 1 to 50 percent and preferably from5 to 25 percent e.g. from 10 to 15 percent based on the total molarproportion of dicarboxylic acid.

Preferably the acidic reagents and thealcoholic reagents are heatedtogether at a temperature sufficient to form a polyester but notsufficient to cause charting. Conveniently a hydrocarbon solvent may bepresent, and especially one that promotes azeotropic distillation ofwater, e.g. xylene. Typically the mixture is heated at temperaturesbetween and 200C. Preferably the mixture is heated until a substantiallyneutral polyester has been formed. The polyester may be mixed withsuitable additives e.g. antioxidants such as toluhydroquime, tertiarybutyl catechol.

The polyester may be cured after mixing with from 0.5 to 2.5 moles e.g.from 1 to 2 moles, per equivalent of ethylenic unsaturation, of avinylic material, preferably styrene. Other vinylic curing materialsinclude methacrylic acid and its esters, diallyl phthalate, triallylcyanurate, vinyl chloride and vinyl acetate. The mixtures may be curedfor example by any conventional method, including heating with benzoylperoxide, or cold curing with methyl ethyl ketone peroxide and cobaltnaphthenate. The cured resin may be postcured at elevated temperatures.

Cured resins according to our invention are useful for bonding fibers,such as glass fiber, carbon fiber, asbestos or other reinforcing fiberespecially in the construction of laminates of improved impact strengthe.g. for use in the building, boat building and vehicle buildingindustries. They are especially valuable for providing surface layerse.g. gel coats. Such coats may be applied before during or after the layup of thelaminate. The compositions are also useful as sealants. Gelcoats may be applied by brushing, spraying or dipping. The resins of ourinvention are also of use for a vaiety of other surface layers andfinishes, e.g. in paints and varnishes which are cured to provide aresinous coatmg.

The invention is illustrated by the following examples: In each examplea spiroacetal of the formula:

was heated with maleicacid, phthalic acid and ethylene glycol at 170C.The temperature was maintained between 160 and 170C until a 90 percentMeOOCCHzCHzCH CHCHzCOOMe decrease in acid value had been achieved. Thetem- Example Example Example 1 2 3 Spiro acetal (mole%) 10 15 25Phthalic Anhydride 40 35 25 Maleic 50 50 50 Ethylene Glycol I00 100 100Styrene 50 50 50 Toluhydroquinone (p.p.m.) 300 300 300 Acid value(uncured) m.g. KOH/gm 39 38 54 Color (uncured) on Gardner scale 6-7 4-56-7 Deflection Temp. (cured) 53C 40C 20C ASTM-D 648 Barco Hardness 86 8348 drop- I ping to l Flexural Modulus 300,000 243,000 32,000 VolumeResistivity ohm.cm. l.2 l0" 2.9Xl0" 7.2Xl0" H,O Absorption in 24 hoursB.S. 2782-MG02G 22 mg. 27 mg. 119 mg.

We claim:

1. A curable composition for use in the preparation of cross-linkedpolyester resins having improved flexibility which consists essentiallyof a. an ethylenically unsaturated linear polyester, and

b. from 0.5 to 2.5 moles of a liquid vinylic curing agent per equivalentof ethylenic unsaturation in said linear polyester,

said linear polyester comprising a compolymer of i. an ester-formingreagent selected from the group consisting of dicarboxylic acids, theiracid anhydrides, their acid chlorides and their transesterifiableesters, and

ii. from 100 to I50 percent molar based on the proportion of said esterforming reagent, of at least one dihydroxy alcohol,

at least part of said ester forming reagent (i) and said dihydroxyalcohol (ii) consists of at least one compound selected fromethylenically unsaturated acids and alcohols in a proportion of from 25to molar percent based on the total molar proportion of said esterforming reagent and wherein at least part of said ester forming reagentand said wherein each of R, R is a divalent organic group selected fromhydrocarbon, alkyl polyoxyalkylene and polyoxyalkylene carboxylategroups and each X is selected from hydroxyl groups and carboxylic acid,acid chloride, acid anhydride and transesterifiable ester groups, saidspiroacetal being present in a proportion of from 1 to 50 percent molarbased on the total molar proportion of said ester forming reagent.

2. A composition according to claim 1 wherein the dicarboxylic acid isselected from fumaric, maleic, phthalic, tetrahydrophthalic,endomethylenetetrahydrophthalic, sebacic, adipic, azelaic, malonic,cyclohexanedicarboxylic, terephthalic, isophthalic, tetrachlorophthalic,hexachloroendomethylenetetrahydrophthalic, and succinic acids.

3. A composition according to claim 1 wherein the dihydroxy alcohol isselected from ethylene glycol, propylene glycol, butene -l,4-diol,butane diols, polyglycols containing from 2 to 50 alkylene oxy units,diols of the formula l l I C1 C1 C1 01 where each n is from 1 to 10 anddiols of the formula:

4. A composition according to claim 1 wherein there is additionallypresent a mono functional compound selected from mono carboxylic acidsand mono hydroxy alcohols.

5. A composition according to claim 1 wherein the spiroacetal is acompound of the stated formula wherein R,R' are each selected fromdivalent aliphatic, cycloaliphatic, aromatic, olefinic, and alkaromatichydrocarbon groups.

6. A composition according to claim 1 wherein the vinylic compound isselected from styrene, methracryllie and esters thereof, diallylphthalate, triallyl cyanurate, vinyl chloride and vinyl acetate.

7. A cross-linked polyester formed by curing a curable compositionaccording to claim 1.

8. A composition according to claim 1 wherein said linear polyestercopolymer contains units which are residues from the polyesterificationof at least one compound selected from the group consisting of glycerol,trimethylolpropane and pentaerythritol.

9. A composition according to claim 2 wherein said dihydroxyalcohol isselected from the group consisting of ethylene glycol, propylene glycol,butene -l,4-diol, butane diols, polyglycols containing from 2 to 50alkylene oxy units, diols of the formula Cl Cl C1 G1 I l l l m0omcHnmH-Q-Q-Nmcmcmmm. c1 c1 c1 01 where each n is from 1 to and diols ofthe formula:

CHzCH2 CH /CHg-CH HO CH CH-C-CH CHOH CHZ CHZ CH2 CHE-CH1 10. Acomposition according to claim 2 wherein said linear polyester copolymercontains units which are residues from the polyesterification of atleast one compound selected from the group consisting of glycerol,trimethylolpropane and pentaerythritol.

11. A composition according to claim 3 wherein said linear polyestercopolymer additionally contains a monofunctional compound selected fromthe group consisting of monocarboxylic acids and monohydroxy alcohols.

12. A composition according to claim 10 wherein R,R' are each selectedfrom divalent aliphatic, cycloaliphatic, aromatic, olefinic andalkaromatic hydrocarbon groups.

13. A composition according to claim 12 wherein the vinylic compound isselected from the group consisting of styrene, methacrylic and estersthereof, diallyl phthalate, triallyl cyanurate, vinyl chloride and vinylacetate.

14. A composition according to claim 7 wherein said curable compositionis cured by addition of benzoyl peroxide at elevated temperatures.

15. A composition according to claim 7 wherein said curable compositionis cured by a mixture of methyl ethyl ketone peroxide and cobaltnaphthenate.

16. A composition according to claim 1 wherein said linear polyesterpolymer is a copolymer of at least one dicarboxylic acid selected fromthe group consisting of fumaric, maleic, phthalic, tetrahydrophthalic,endomethylenetetrahydrophthalic, sebacic, adipic, azelaic, malonic, cclohexanedicarboxylic, tere hthalic, isophthalic, etrachlorophthalic,hexac loroendomethylenetetrahydrophthalic, and succinic acids, with atleast one dihydroxyalcohol selected from the group consisting ofethylene glycol, propylene glycol, butene--l,4-diol, butane diols,polyglycols containing from 2 to 50 alkylene oxy units, diols of theformula :1 :1 p1 :1 11 ocH,oH,)..NH- Q-muomomonn.

l Cl Cl 01 01' where each n is from 1 to 10 and diols of the formula:

in the presence of at least one spiroacctal of the formula:

o-om errata! MoOOCCHzCIhCH o oHcmcooMe O-CHz CH2O and the curing agentis styrene.

UNITED STA'lES PATENT oFFmE CEREHFKCNEE 0% {301m EQTWN Patent No. 3 v Dd January 3O 1973 InVentor(s) KENNETH WILLIAM ROCKEY It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

In the left column, on the title page insert the following:

-Claims priority British Application No. 42027/69 filed August 22 -l969-Replace the formula which appears in Column 4 lines 60-63 Column 5 lines30-33 and Column *6 lines 33-35 with the following formula:

un-cg: on, c n:-om

noon crr-c-cn CHO}! Signed and sealed this 3rd day of July 1973.

(SEAL) Attest:

EDWARD M.FLETCHER-,JR;

Ren T I Attestln Offi 6 gtme e CtiIlg Commissioner of Patents FORMPO-1OSO (10-69] USCOMM OC 5O375 p59 w us, GOVERNMENT PRINTING OFFlCE:was o-ass-sas.

1. A curable composition for use in the preparation of cross-linkedpolyester resins having improved flexibility which consists essentiallyof a. an ethylenically unsaturated linear polyester, and b. from 0.5 to2.5 moles of a liquid vinylic curing agent per equivalent of ethylenicunsaturation in said linear polyester, said linear polyester comprisinga compolymer of i. an ester-forming reagent selected from the groupconsisting of dicarboxylic acids, their acid anhydrides, their acidchlorides and their transesterifiable esters, and ii. from 100 to 150percent molar based on the proportion of said ester forming reagent, ofat least one dihydroxy alcohol, at least part of said ester formingreagent (i) and said dihydroxy alcohol (ii) consists of at least onecompound selected from ethylenically unsaturated acids and alcohols in aproportion of from 25 to 75 molar percent based on the total molarproportion of said ester forming reagent and wherein at least part ofsaid ester forming reagent and said dihydroxy alcohol consists of atleast one spiroacetal compound of the formula
 2. A composition accordingto claim 1 wherein the dicarboxylic acid is selected from fumaric,maleic, phthalic, tetrahydrophthalic, endomethylenetetrahydrophthalic,sebacic, adipic, azelaic, malonic, cyclohexanedicarboxylic,terephthalic, isophthalic, tetrachlorophthalic,hexachloroendomethylenetetrahydrophthalic, and succinic acids.
 3. Acomposition according to claim 1 wherein the dihydroxy alcohol isselected from ethylene glycol, propylene glycol, butene -1,4-diol,butane diols, polyglycols containing from 2 to 50 alkylene oxy units,diols of the formula
 4. A composition according to claim 1 wherein thereis additionally present a mono functional compound selected from monocarboxylic acids and mono hydroxy alcohols.
 5. A composition accordingto claim 1 wherein the spiroacetal is a compound of the stated formulawherein R,R'' are each selected from divalent aliphatic, cycloaliphatic,aromatic, olefinic, and alkaromatic hydrocarbon groups.
 6. A compositionaccording to claim 1 wherein the vinylic compound is selected fromstyrene, methracryllic and esters thereof, diallyl phthalate, triallylcyanurate, vinyl chloride and vinyl acetate.
 7. A cross-linked polyesterformed by curing a curable composition according to claim
 1. 8. Acomposition according to claim 1 wherein said linear polyester copolymercontains units which are residues from the polyesterification of atleast one compound selected from the group consisting of glycerol,trimethylolpropane and pentaerythritol.
 9. A composition according toclaim 2 wherein said dihydroxyalcohol is selected from the groupconsisting of ethylene glycol, propylene glycol, butene -1,4-diol,butane diols, polyglycols containing from 2 to 50 alkylene oxy units,diols of the formula
 10. A composition according to claim 2 wherein saidlinear polyester copolymer contains units which are residues from thepolyesterification of at least one compound selected from the groupconsisting of glycerol, trimethylolpropane and pentaerythritol.
 11. Acomposition according to claim 3 wherein said linear polyester copolymeradditionally contains a monofunctional compound selected from the groupconsisting of monocarboxylic acids and monohydroxy alcohols.
 12. Acomposition according to claim 10 wherein R,R'' are each selected fromdivalent aliphatic, cycloaliphatic, aromatic, olefinic and alkaromatichydrocarbon groups.
 13. A composition according to claim 12 wherein thevinylic compound is selected from the group consisting of styrene,methacrylic and esters thereof, diallyl phthalate, triallyl cyanurate,vinyl chloride and vinyl acetate.
 14. A composition according to claim 7wherein said curable composition is cured by addition of benzoylperoxide at elevated temperatures.
 15. A composition according to claim7 wherein said curable composition is cured by a mixture of methyl ethylketone peroxide and cobalt naphthenate.